Meta

Tag: motocross bike

Looking to buy a red dirt bike but not sure which one is better? While the CRF250R and CRF250X started off on similar platforms, there are some major differences between the two that make each better in its own way. The first question you should ask yourself is, “What kind of riding are you looking to do with it?”

Suspension – Racing or Trails?

Having the right suspension for the job will make all of the difference between two bikes. While this isn’t the only difference, it’s probably the most important. The CRF250R is a motocross bike; therefore it will have stiffer suspension and valving set up for racing on a track with big jumps and whoops. It’s still not going to fit you perfectly right out of the box, but it’s going to be a lot better of a starting point than if you were to get the 250X.

If you’re looking for something more than the typical, boring, air-cooled four-stroke trail machine, the CRF250X may be just the answer. It began production with the same frame design and style of the CRF250R, including the higher performance inverted-fork and shock set-up. While it may have better and more easily adjustable suspension than most other trail bikes, it’s still going to be pretty soft so you can go on long trail rides without getting worn out from stiff suspension bucking you around.

Engine

CRF250R

Do you like a fast-revving, high-horsepower, race engine, or do you want something that’s smoother with a broader power-band so it won’t scare you? For having almost the same engine design, there’s yet again some major differences between the two. The 250R has a larger stroke (smaller bore), a little higher compression, hotter camshaft, a close-ratio transmission, and EFI starting in 2010. These things all add up to making the motocross version of Honda’s 250F more snappy and begs the rider to twist the throttle.

On the flip-side, the CRF250X still has the same basic engine design. A less-radical cam makes it more trail friendly for smoother power, along with the lower compression. A wider transmission ratio also makes it great for trails, both tight and high-speed. A lower-flowing intake and exhaust set-up combine to make this bike tamer for the beginning riders in mind. The exhaust is considerably quieter, and has a spark-arrestor for state trail riding.

Light-weight vs. Trail Amenities

CRF250X

The more trail riding you want to do, the more accessories you’ll want to have on your bike. However, lightweight is the reason why the CRF250R handles so well. The options that are exclusive to the 250X that add the most weight are a kick-stand, electric start/battery, headlight/tail-light, airbox, larger-capacity gas tank, and exhaust system. Most of these mentioned are highly desirable for trail riding, but you will feel the weight difference if you ride both bikes back-to-back.

So the question is, what are the options worth to you, and how much off-road/trail riding will you be doing? A lot of riders that like the race form of the 250R will take it and add a few things to make it more ride-able in the woods and absolutely love it. However, if you are older and prefer E-start, a kick-stand, and soft suspension, you will enjoy the 250X more, even if it is down on power a little.

“Loading up” is a common problem for 2-stroke dirt bikes and snowmobiles. If you don’t know what it means or haven’t heard the term before, it’s usually when you let the engine sit or idle for more than a minute and when you go to rev it, it coughs and sputters. This feedback makes for terrible throttle-response, and will eventually foul the spark plug.

To temporarily fix this, assuming the bike is fully warmed up, give it a few quick bursts of WOT (Wide-open-throttle). This will clear it out, and should run like normal again. However, for those of you that want to fix this problem long-term, you’re going to have to spend a little more time, as well as a couple bucks…

The reason your two-stroke ‘loads up’ is because not all of the gas gets burned through the cylinder, so it just sits in the crankcase. When you give it some throttle, the fuel/air ratio is too high, causing it to blubber and sputter until it clears out this excess fuel. When there’s too much fuel going through the cylinder at the same time, the spark plug cannot burn all of it, thus resulting in a fouled plug. A spark plug is fouled when the jetting is too rich, and the tip of it will come out black and often wet (Click here to read more about Jetting).

Honda CR125 is a common bike that loads up.

So how do I prevent this from happening? The pilot jet is almost always the culprit. Many two-strokes (Honda for the most part) come jetted rich from the factory. This is probably to prevent engine failures, but it often causes more problems and headaches. A properly jetted dirt bike will have more power, much better throttle response, and no plug fouling.

Since the pilot jet is too rich, pull the float bowl off of the carburetor and unscrew the pilot jet. It will usually have a smaller number stamped on it, such as 42 or 55 (may require a magnifying glass). Go to your local bike shop and buy a couple jets smaller for it. Don’t worry, they’re only a few bucks each. To get an idea of what size you need, first check your manual if they have any jetting specs or recommendations. The internet is incredibly resourceful, so check there as well. In the end, every bike is different, so you may just have to try a few jets to see what works the best. Just remember that a rich pilot jet will cough and hiccup, while a pilot that’s too lean will bog off idle. Either one will have poor throttle response, so having the right jetting will go a long ways.

If re-jetting won’t get rid of the loading up problem, there’s probably something else wrong with your bike. Check and make sure the air filter is clean, the reeds are not cracked, the engine has good compression, and you are using fresh gas that has the right Pre-mix.

Since there’s not much hope in the economy coming back in the near future, dirt bikers are resorting to things that will give them the best bang for their buck. As a result, 125cc two-strokes have been rising in the used market. Why? Well, it’s pretty simple, actually. First of all, you can rebuild the top-end for $150 or less, which can be done in your garage with a little mechanical motivation and patience. They are great dirt bikes to start out on for motocross, as they teach you how to control the throttle, clutch, and controls. Probably the best part about a 125 2-smoker is that they’re an absolute blast to ride! They’re light, quick, snappy, and besides, who doesn’t like the smell of race gas and pre-mix in the morning?!

Which Decade?

Yamaha hasn’t changed their 2-strokes for a while. However, this doesn’t mean it’s outdated. In fact, that’s quite the opposite, as Yamaha has been building quality 2-stroke motocross bikes for years. As long as they make them, riders continue buy them. They are often the first dirt bikes to sell in a dealer, but let’s take a look at why these bikes are so popular in the first place.

1990’s YZ two-strokes are fairly similar. In ’96 they made some changes that lasted until the end of 2001. These are still considered some of the best motocross bikes, especially the 1999 model. They are fast, reliable, and are just a great overall bike.

In 2002 the frame changed, making it lighter, narrower, and more flick-able. However, many people didn’t approve because it switched to a 5-speed transmission. 125’s have a narrow power-band as it is, and some riders just like having that extra gear.

2005 and 2006 are biggest years for the Yamaha YZ125. In ’05 they changed to an all aluminum frame, made some engine changes, as well as changing back to a 6-speed transmission.

2006 Yamaha YZ125

Power

Power has never really been an issue when it comes to the YZ125. In amateur ranks, these small-bore two-strokes can hold their own against 450’s with the right rider. Of course it can be harder to ride them faster, but they have the ability, and it’s extremely fun doing it. Although 125’s are known to have little to no bottom-end power, the YZ125 has always seemed to have a little more torque down low than the others in its class, making it manageable if you need to lug it in tight areas. Once you get to the mid-range you can start to feel the inner-beast come alive, especially on the later models. As soon as you hit the power-band on one of these tiddlers, you’ll know why they are so addicting. It may scare you at first if you’ve never ridden a two-stroke motocross bike, but you’ll be begging to do it again and again until there’s no more premix in the tank… Throw a pipe on this thing and get it properly ported, and you have race-ready engine on your hands (not that it isn’t with a stock engine).

In 2005, the YZ125 got a new engine and carburetor, which greatly improved the bike. It’s so crisp and fast that you don’t need to touch the bike to be competitive. Although, as the saying goes, it’s easier to make a fast bike faster… Slap a pipe on there, get it ported, run some race-gas, re-jet, and she’s ready to haul the mail!

Handling

While it’s light, fast, and flick-able, some people don’t like the way YZ125’s handle as much as other late-model 125’s. The CR125 has been at the top of its class in the handling department since the 3rd generation chassis came out in 2002. That bike handles extremely well with comfort. The 2002 and newer YZ125 are not far behind though, so don’t let that be the determining factor.

2005 was the first year of the aluminum frame, which is still claimed to be one of, if not the best 125 two-stroke made. It’s lighter, faster, handles better, and just overall rides more like a modern motocross bike.

Suspension

Yamaha continues to provide top-notch suspension in their motocross bikes, and the YZ125 is no different. The older bikes from the 90s left something to be desired compared to modern mx bikes, but in the 2000’s they have some of the best suspension out of the box. Bottoming-resistance is one of the leading factors of it being at the top of its class. The ride isn’t as harsh as some of the other bikes, but like any other motocross bike, you will want to get it re-valved if you weight less than 140lbs or more more than 170lbs depending on what kind of riding you do.

In 2006, which was the last year of any major updates, the YZ125 received new SSS forks, which are considered a big upgrade. If you can find a good deal on clean ’06, buy it! If you find a nice ’05, I would definitely buy that too. For someone that’s not a pro rider, you probably won’t notice much of a difference between the two. Besides, most racers get their suspension re-valved for their weight and riding style anyway.

You Shouldn’t Get A YZ125 If You:

Don’t like mixing gas or the smell of premix

Want a smooth and very predictable power-curve

Like checking valve clearances

2001 Yamaha YZ125 2-Stroke

I’ve owned my share of YZ125’s, and they’ve all been great. The most reliable motocross bikes I’ve owned, and they’re just so much fun to ride. Of course, the newer the better, but even a 1999 YZ125 is a great bike to get started in this awesome sport. Check out my other articles on how to find deals on used dirt bikes!